Buying a Manual Transfer Switch

Q: What options should I consider when buying a manual transfer switch?

A: You should consider the following options:

Type

Kits (20-50A, 6-10 branch circuits) - These include a selected circuit transfer switch (see below), power inlet, and power cord. These indoor transfer switch kits are designed for fast installation in residential and small business applications.

Selected Circuit (20-50A, 6-10 branch circuits) - Designed for fast installation, these transfer switches transfer power to selected circuits in your load center. The flexible conduit whip attaches easily to the load center, and all wires are clearly marked. Simply select the circuits in the load center needed in an emergency and connect them to the wire leads. Ideal for residential and small business applications with an existing load center.

Single Circuit (15-50A) - These transfer switches are ideal for providing back-up power to furnaces or sump pumps, as well as other single-circuit applications. Economical and easy to install.

Main/Sub Transfer Panels (30-125A) - These models combine a circuit breaker box and a transfer switch. Suitable for use as a main panel or sub-panel. Service entrance rated and three pole GFCI models are available.

Generator Ready Load Centers (150-200A) - These models combine a transfer switch and load center in one convenient package. Includes a 150A or 200A utility main breaker and a 30A - 125A generator breaker. Provision for up to 38 branch circuits. Service Entrance Rated. Ideal for new residential and small business applications.

Whole House or Business (30-400A) - These switches are ideal for transfering power for your entire house, small business, garage, or pole-barn. Alternatively, these switches can be used to transfer power for an entire sub-panel in your home or business.

Commercial and Industrial (30-4000A) - These switches are designed for commercial, industrial, agricultural, telecom, and municipal applications. Single and three phase up to 600V. Open Transition (break-before-make) is standard. Numerous options available on select series, including Service Entrance Rated, Closed Transition, Delayed Transition, Dual Source, and Bypass Isolation.

Amperage/Watts/Voltage/Phase

What amperage and watts are available from your generator? What utility amperage do you have? Does your generator support 120V only or 120/240V? Is your electrical system single or three phase?

Branch Circuits

How many branch circuits do you want to power from your generator? What amperage do those circuits need to be?

Power Inlet

How are you going to connect your generator to your transfer switch? Do you want a power inlet built into the transfer switch? Do you want a power inlet box separate from the transfer switch? Be sure the NEMA configuration of your power inlet corresponds with the NEMA configuration on your generator receptacle (L5-20, L14-20, L5-30, L14-30, etc.)

Watt Meters

Do you want watt meters on your transfer switch?

Cabinet Type

Will the transfer switch be inside or outside? Outside cabinets should be NEMA 3R. NEMA 4 and 12 are also available for some commercial and industrial transfer switches.